Automatic flow control system for ore concentrators



P 1952 E. c. BITZER 2,609,096

AUTOMATIC FLOW CONTROL SYSTEM FOR ORE CONCENTRATORS Filed Sept. 18, 19482 SHEETSr-SHEET 1 n-m 1N VEN TOR.

[o'mund C, Bi/zer ATTORNEY E. c. BrrzER v Sept. 2, 1952 AUTOMATIC FLOWCONTROL SYSTEM FOR ORE CONCENTRATORS Filed Sept. 18, 1948 2 SHEETS-SHEET2 l l I l I l l l I l I [ea mL/na/ C. B/fzer w wk Patented Sept. 2, 1952PATENT OFFICE AUTOMA TICFhOW CONTROL SYSTEM FOR T .1 J ORECONCENTBATORSEdinnnd'. CL Bitzer; Golden, 0010., assignor to Colorado IronworksCompany, Denver, 0010., a'corp'or'ationcf Maine ApplicationSeptember 18,1948, SerialNo. 49,928"

. e I 1 v This invention relates to oreconcentratorsand dewaterersand-more.; particularly to improvementsrin controlling flow througha-concentraton such as shown in'the application Serial No: 20,472, filedApril 12; 19%8,by ArthurJ Weinig. V

.In -the application identified, the concentrates are delivered from-theccncentratorioutlet pipe,

trator must, ofcourse, bear an exact relationship toitherate of feeclof'pulp to the concentrator in'-:

order that the concentrator operate under opti-' mum conditions. If, forexample, the rate of discharge fromthe concentrator exceeds theirate offeed of pulp thereto; the pump will tend to withdraw all the pulpthrough the concentrator and there will thus be no gangue or tailingsoverflow from the concentrator and hence'no-concentra tion. On the.other band ifthe rate of flow through the pump is less thanrequired-foroptimum concentration, then there will beexcessive overflow from theconcentrator and'much valu able ore will be-carried along with-thetailings; It is apparent, therefore, that withany Dredetermined'rate ofp'ulpflflow to the concentrator; an

exact differential pressure must be maintained between theconcentratoroverflow and the end of thevconcentrator discharge'pipein order that theconcentrator operate most emciently.

In any-system which employs a'pumptozcarry the concentrates-the pumpis-subjectecl toconsiderable' wear with its attendant! change inpumping, capacityibecauseof thefiabrasivenature: of theconcentrateswhich pass therethrough; It. would therefore be of furtheradvantage to'el-iini nate this pump", if possible;

The principal object of the present invention, therefore, is to providea-nimprbved flow" control for a concentrator:

Anotherobjectis" to relate a? concentrator and dewa-te'rer in suchmanner that gravity head projdiic'es a" fiovflthrough the concentratorwhich head is" partially balanced by, liquid in the dc- Waterer';

. 1 Claim. (Cl. 209 455) Another object is to produce optimum flowthrough a concentrator without employing a v pump'which conveys solids.

A: further object is to relate the rate-of discharge'fro n aconcentrator to the rate of feed of pulp-thereto by anarrang'ementWhichis auto-;

matic in operation and effects an exactnnchanging".ditferentialpressurewhich produces optimum flow' through the concentrator. v

Another ohjectis-to-provide an arrangementof a concentratorand'dewatererin which the rate oil now; through the concentrator may be"varied,

as desired, without the use ofza solids conveying pumypor solidsconveyingvalve, i

Another object istoiarrange'the' discharge of aconcentrator with respectto a dewaterer in. suchrnanner that clogging of' theconcentratordischarge is eliminated.

Still further objects will become more apparent from a consideration ofthe description to follow, the} appendedv claim, and the{ accompanyingdrawing-,in-which: A

,,Ffigure.1' is ca planlview showing the relative positions of theseveral elements; Figure 2- is a section taken online 2-2 Figures land'2; and:

Figure 3 is aside elevation taken'online 3 Figure nl with parts thereofbroken away and shown in section.

In the drawing reference character C,desig.-

nates a concentrator of the general type shown and-describecliin theapplication above identified andifp is. a dewaterertor classifier of thescrew typelasishown at; l -Liwith the conventional discharge.l2fat1itsupperendover which flows dewat'ered solids. This" dewatererisrepresentative of such devices of which there are many specificallydifferent constructions available-and which differ from the" one shownprincipally inthis;

V that rake's'. or f conveyor belts are substituted'for Concentrator; Chas an overflow spout 0; near itsjtop ove'r whichflbw's isurplus waterand gangue or tailingsfand' anloutlet pipe in" at" its bottom throughwhichflows .theiconcentrates for delivery to the-dewaterer. Thedewaterer is? provioldwith an' outlet-lt lielowdevel LC ofthefconcentrator and" a van-e15 isconnected thereto which, by proper;adjustment;- will' niaintair'iany desired levelintthe 'dewaterer such asthe level LD; It"

is-ttoiibe'" partieularly"notedlthat valve totcon'veys watenonly';rather than solids; becauseiseparationof solids and the liquiddelivered-fronithe: cone centrator takes place in the dewatererythesolids v being dewatered and conveyedover upper edge [2 and the Waterbeing discharged through outlet specific gravity of the material in theconcen-' trator and pipe 10, and the resistance which the pipe andconcentrator ofier to fiow. This head concentrator and dewaterer areconnected together by an inclined pipe l0. This inclined pipe forms theshortest possible straight connection between the two machines and thusprevents any clogging taking place therein as might occur with the useof a horizontal run of pipe, elbows, or other fittings which tend to.obstruct fiow.

While the invention has been disclosed witha dewaterer having a variablelevel, it is to be understood that other devices which provide abalancing fluid column could also be employed.

is partially balanced by the head of the material 7 in the dewatererwhich is similarly determined, the distance between LD and the bottom ofpipe 10 being one of the factors.

The relative levels of LC and LD will, of course, vary according to thenature of the ore being treated and the rate of flow desired through theconcentrator. the flow and raising the level will decrease the flow. Nocountercurrent flow should ever exist in pipe In which would carry finesupwardly to be ultimately lost in the gangue or tailing overflow 0.Normally the level LD would be below LC by a distance it to produce thedesired fiow. It may of course be lowered by a distance h which isdetermined by the position of outlet 1 3. Also, in some cases it may bedesired to raise this level a distance h" above level LC. For example,if the specific gravity of the material in the concentrator and itsdischarge pipe is considerably greater than the specific gravity of thematerial in the dewaterer then a theoretical static balance of therespective columns would occur when the two heads are in proportion totheir specific gravities, that is level LD would be higher than LC. Thiswould produce no flow, how-ever,

hence h" would always be of such a value that some differential pressurewould exist to produce flow.

A pump I4 is connected to overflow I3, but it is apparent that this pumpdoes not control level LD in the embodiment previously disclosed. Thepump merely delivers discharged fiuid to any convenient point in thesystem, for example, through pipe to a tank T for subsequent return tothe concentrator through valve P. This return is illustrative only andit is apparent that the water from overflow l3 may be delivered to anyplace desired and that water supplied by valve 1?,when employed, may bereceived from any suitable source. The control of level LD by means of avalve has been shown for illustration only, this beingprobably thesimplest form in which the invention may be disclosed. It now becomesapparent that many other forms of level controls could be employedsuch'as an adjustable weir or adjustable syphon having one leg thereofwhich would determine level LD. Also, an adjustable float could beemployed which would maintain level LI) as desired, as well understoodin the art'of level controls. Under certain circumstances it may also bedesirable to control the level LD responsive to changes in the specificgravity of the material in the concentrator. Thus, if a portion of thepulp feed should change in specific gravity, the rate of flow throughpipe would change if the level LD remained constant. Any suitable meansknown in the art, which would sense such change in specific gravitycould be employed to regulate valve [5 so that flow conditions throughpipe l0 would remain constant even with variable specific gravity of thepulp.

It is to be particularly noted, also, that the Lowering of level LD willincrease.

Thus, the dewaterer might have a secondary function of classification ofthe ore concentrates hence the term dewaterer as used in the claim is tobe given its broadest and most generic meaning within the spirit of theinvention.

' The present invention is to be distinguished from prior artarrangements wherein a concentrator delivers concentrates by gravityfiow to a dewaterer. In these prior art devices there is no control ofan optimum level of liquid in the dewaterer. Since the concentrateswhich are delivered to the dewaterer may be, for example, 50% solids and50% water, and the dewatered material which is conveyed over thedischarge l2 of the dewaterer may contain of the order of 80% solids, itbecomes apparent that there is an excess of water being continuouslydelivered to the dewaterer which must be discharged somewherein thesystem. The gangue overflow in the ;concentrator being the only placewhere this centrator there is a flow of water in the opposite directionthrough this conduit. This counterfiow of water carries with it certainof the fines which are carried over the gangue overflow of theconcentrator and are thus either lost or necessitate 1 W furtherseparation from the gangue if it is desiredto recover them. The presentinvention, on the other hand, provides an exact control of flowconditions in the concentrator discharge conduit.

The provision of discharge l3 and control of level LC provide anarrangement which effects exact control of the fiow conditions indischarge conduit l0. Thus, as previously mentioned, if it is desired torecover the fines along with the concentrates, which is usually thecase, the flow conditions can .be so regulated that no counterfiowexists in conduit I0 and all of the fines will :be delivered to thedewaterer. It is, of course, apparent that the present invention couldbe employed, also, to achieve substantially the same results asdescribed for the prior art. Thus, if it should not be desirable torecover the fines; or a laterally spaced relation, the concentratorhaving agangue overflow at certain level and a con centrate dischargeopening at a lower level, the gangue overflow and the concentratedischarge opening being in communication by a teeter col- 6 REFERENoE sCITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,031,113 Garred July 2, 19121,491,296 France Apr. 22, 1924 1,541,237 Trott June 9, 1925 1,917,819Barr July 11, 1933 2,302,588 Weber Nov. 17, 1942 2,417,660 Remick Mar.18, 1947 2,460,801 Bitzer Feb. 8, 1949

